This invention pertains to a training aid device for use in increasing a player's ability in the game of billiards, which name in all of the following includes the game of pocket billiards. This invention pertains specifically to the aspect of the game referred to as "banking" which is the rolling of a ball into a limit of the game table known as a cushion for the purpose of having the ball return from such cushion along a desired path on the table. The ability to direct the ball into the cushion at such a point and in such a manner that the path of its roll from the cushion may be predicted is a desirable ability in billiard games.
Many players of low or fair ability incorrectly believe that a desired "banking" will result if the ball is directed to the cushion edge at that point at which the acute angle of the imaginary line between the ball and the point on the cushion is equal to the acute angle of the imaginary line between the desired destination and the same point on the cushion. This would be essentially true if the cushion were of a polished and inflexible material such as ivory. This is not true to varying degrees because the cushion is felt covered rubber, which allows two factors to affect the angle at which the ball returns from the cushion. The rubber cushion is compressed when the ball hits it, and in returning to its normal configuration will deflect the ball from its theoretical bank line an amount related to the speed of the ball when it hits the cushion. The second factor is that any spin which the ball has causes the felt on the cushion to grab the ball during this contact and to deflect the ball from its theoretical bank line, an amount related to the angle of the ball's approach to the cushion, the speed of the spin, and the direction of the spin. Thus by combination of speed and spin effects the ball may bank at either a higher or lower angle than the theoretical.
Three conventional methods of determining the theoretical banking point are: attempting to imagine the equal acute angles previously described; attempting to use "diamonds" which are equally spaced markers on the table rail behind the cushions, in which case a mental calculation of some difficulty is required; using a protractor to describe the angles of the banking point on the table in chalk. The present invention is superior to these methods as it does not require an ability to imagine the angles, an ability to calculate, the ability to read a protractor, nor does it require marking the table.
A basic object of the device is to provide a means of simply, quickly and accurately locating the theoretical banking point on the cushion for a ball in any location on the table which ball is desired to be banked to a specific location such as a pocket.
A second object of the device is to provide both a rapid means of adjustment for various angles of banking and at the same time one which may be used correctly with a minimum of training and adjustment ability.
A third object of the device is to provide a means for analysis of the effect of various speeds and spins imparted to the ball, to the actual direction of the ball on leaving the cushion.
A fourth object of the device is to assist the player in improving his proficiency in understanding where the ball must be aimed relative to the theoretical banking point when various options of ball speed and spins are used, all in order for the ball to follow a desired path from the cushion in a bank shot. A further object of the device is to provide an inexpensive device for the improvement of a player's ability to bank a ball in a billiard game.